Sure, the gyroscope in your smartphone is great for whizzing past the competition in Need For Speed. But did you know that it can also be used to eavesdrop on your conversations?

Researchers from Stanford University and Israel's defense research group, Rafael, have developed a way to turn a smartphone's gyroscopes into crude microphones. They will present their findings at the Usenix security conference next week.

What they discovered was this: not only were the gyroscopes sensitive to phone vibrations (to figure out the orientation of the device, for instance), they could pick up the frequency of minute air vibrations around them as well. This is what they were capable of, according to an article on Wired:

It works just well enough to pick up a fraction of the words spoken near a phone. When the researchers tested their gyroscope snooping trick's ability to pick up the numbers one through ten and the syllable "oh"—a simulation of what might be necessary to steal a credit card number, for instance—it could identify as many as 65 percent of digits spoken in the same room as the device by a single speaker. It could also identify the speaker's gender with as much as 84 percent certainty. Or it could distinguish between five different speakers in a room with up to 65 percent certainty.

Apps typically need to ask users for their permission to access certain hardware components of their device — the microphone, for instance, or the GPS chip. But gyroscope access, worryingly, requires no permissions at all. [Wired]